Pros & cons of clockwise V anti-clockwise if you will.
Coming from the east so best place to start from.
And pics too!
Ta
I've only done it clockwise but I can't see it making much difference. Epic XC route either way.
Anticlockwise you'll come down the Das which is steep and bound to be fun but a lot of height lost very quickly. On the other hand, carrying up the Das is horrid.
Do it on a nice day whatever you do!
As Crispo says. The push/ride (if you are Danny Macaskil!) up Y Das is the killer when done clockwise. However this does allow for the long fast rough descent past the reservoir, the awesome descent into Llanbedr from Crug Mawr, and the nice climb and descent from Bwlch Trumau. I wouldn't really consider doing it anti to be fair. Make sure you pick a dry sunny day and not after rain!
If coming from M4 side then start in Llanbedr. If coming from North then maybe come in from Talgarth side is marginally better